A film depicting the defence procedures of the West Sussex Home Guard. The narrative is centred around the fictional town of Onebridge and uses commentary to introduce the staged scenes.

The local Home Guard Battalion Commander chairs an emergency meeting in the fictional town of Onebridge. Representatives from local civil defence groups and public service bodies, including the food executive, the medical officer of health, the town surveyor and the district transport officer, all acknowledge their roles in the event of an enemy invasion. The 10th Battalion of the Wessex Home Guard call for volunteers - a posted letter reads, "those with expert knowledge of building and construction are needed to assist in the making of field works and defences." Members of the Home Guard battalion are filmed in various outdoor training exercises - they practice on the firing range, handle numerous weapons including a Browning machine gun, a Browning automatic and bayonets, and learn about map reading. Platoon commanders plan the network of defence in the countryside around Onebridge. Later, these lines of defence are tested by a visiting General who upsets expectations by walking rather than driving to the roadblocks. The Home Guard respond positively to the General's surprise tactics - an animated map details their response. The General joins Colonel Gundar (?) on a tour of inspection, visiting the camouflaged gun positions, roadblocks and trip wires which populate the countryside surrounding the arterial roads. A mobile reserve receives its orders before the film ends abruptly - the end of the film appears to be missing.

The production context of [Procedures in the Event of an Enemy Attack] (1941?) is unknown but it is highly probable that it was a training film made and/or commissioned by the West Sussex Home Guard. Screen Archive South East holds three other training films which are in the same vein - they are all called West Sussex Home Guard (1941?). One of these films is known to have been produced by a commander of the West Sussex Home Guard - commanders were responsible for the training of new recruits and films were one of the inventive methods employed by some to do this.

In May 1940 an appeal was made for men aged between 40 and 65 to join the Local Defence Volunteers (LDVs - later known as the Home Guard). By the end of June nearly a million and a half men had been recruited nationwide, creating a force intended to delay an enemy invasion until the Armed Forces could be mobilized. The Home Guard was established at a time when the threat of such an invasion was very real. Initially however the Home Guard was poorly resourced - weaponry mostly consisted of First World War relics, bayonets and imported guns. In addition, the Home Guard came to be nicknamed 'Dad's Army' because the majority of volunteers were too old to serve in the regular army. [Procedures in the Event of an Enemy Attack] (1941?) therefore provides an interesting record of the Home Guard, offering positive images of the weaponry, the troops and the activities of the civil defence body in West Sussex.

Screen Archive South East houses films which record the work of the Civil Defence Services during the Second World War, namely Leatherhead Newsreel (1940 - 1945) and Civilians in Uniform (1946).